Should a Fish Tank Filter Be Fully Submerged? (Find Out)

submerging a fish tank filter

The placement of a fish tank filter is a critical decision that can impact the overall health and well-being of the aquatic inhabitants. One aspect that often sparks debate among aquarists is whether a filter should be fully submerged or not.

This question is not as straightforward as it may seem, as the answer depends on various factors such as the type of filter being used and its intended purpose. To truly understand the implications of fully submerging a filter, it is necessary to explore the different types of filters available and the services they provide.

By delving into the pros and cons of each option, we can shed light on this intriguing topic and help aquarists make informed decisions to promote optimal filtration and a flourishing aquatic environment.

Key Takeaways

  • Not all filters need to be fully submerged in a fish tank, as it depends on the type of filter and its function.
  • Air-powered filters should be fully submerged for better stability and oxygen distribution in the tank.
  • Gravel filters should also be fully submerged as they fit under the gravel substrate and distribute oxygen and current evenly.
  • Internal filters can be placed underwater and take up less space in the room, while hang-on-back filters and canister filters are external options that filter the water outside the tank.

Submerging Filters in the Fish Tank

filtering water in fish tank

Submerging filters in the fish tank is a crucial consideration when setting up an aquarium, as it directly impacts the filtration efficiency and overall water quality.

Proper filter maintenance and choosing the right filter are essential for maintaining a healthy aquatic environment. Different types of filters have specific requirements regarding submersion.

For instance, air-powered filters should be fully submerged in the tank to ensure stability in the water currents and even oxygen distribution. Gravel filters, on the other hand, should also be fully submerged under the substrate to evenly distribute oxygen and currents.

Internal filters, such as air-powered and under-gravel filters, can be placed underwater and are effective at their job.

Hang-on-back and canister filters, which are external filters, filter the water outside the tank and cannot be fully submerged.

Proper submersion of filters is vital for efficient filtration and maintaining an optimal environment for the fish.

Submerging an Air-Powered Filter

When considering the submersion of filters in a fish tank, it is important to specifically address the submerging of air-powered filters due to their unique characteristics and benefits.

  • Air-powered filters should be fully submerged in the fish tank. Submerging the filter provides better stability in the tank currents, ensuring proper oxygen distribution.
  • These filters are particularly suitable for smaller fish that prefer calm water.

Air-powered filters offer several advantages over hang-on-back filters. While hang-on-back filters are a common type of filter, air-powered filters provide better stability and are more effective in distributing oxygen evenly throughout the tank. Additionally, air-powered filters are often paired with a stronger filter for optimal tank cleaning.

Submerging a Gravel Filter

underwater gravel filter operation

A gravel filter should be fully immersed in the fish tank to effectively distribute oxygen and maintain water currents evenly. This placement offers several benefits for aquarium enthusiasts.

Firstly, underwater placement helps to hide the filter from view, creating a more aesthetically pleasing tank.

Secondly, submerging the gravel filter ensures that it is properly positioned beneath the gravel substrate. This allows the filter to efficiently distribute oxygen throughout the tank, promoting the health and well-being of the aquatic species.

Additionally, underwater placement helps to evenly distribute water currents, preventing stagnant areas in the tank and aiding in the removal of debris.

However, it is important to consider the potential drawbacks of gravel filters, such as the need for regular maintenance and the potential for clogging.

Internal Filters

To further explore the filtration options for aquarium enthusiasts, the discussion now turns to internal filters, which offer efficient water filtration within the fish tank. These filters, also known as submerged filters, are devices that hang on the back of the tank and perform the same function as other filters. They take up less space in the room and are effective at their job.

Benefits of Internal Filters:

  • Efficient water filtration: Internal filters are designed to effectively remove impurities and provide clean water for the fish.
  • Easy maintenance: These filters are easily accessible for cleaning and maintenance, making it convenient for aquarium owners to keep their tanks in optimal condition.
  • Improved water circulation: Internal filters create water movement within the tank, which helps in oxygenation and prevents stagnant areas where debris can accumulate.

Internal filters are a popular choice for aquarium enthusiasts due to their efficient filtration capabilities, ease of maintenance, and ability to improve water circulation within the tank.

Hang-on-Back Filters

aquarium filters for easy installation

Hang-on-Back filters, also known as HOB filters, are a commonly used type of external filter that efficiently removes impurities from the water outside the fish tank. These filters are designed to hang on the back of the tank, providing a convenient and space-saving filtration solution. HOB filters work by siphoning water from the tank into the filter chamber, where it passes through various media to remove debris, chemicals, and waste. The filtered water is then returned to the tank through a spillway.

One important factor to consider when using a HOB filter is the filter flow rate. This refers to the speed at which the water is processed through the filter. The flow rate should be appropriate for the size of the tank and the needs of the fish. It is important to choose a filter with adjustable flow settings to ensure optimal water circulation without causing excessive agitation or stress to the fish.

Maintenance requirements for HOB filters include regular cleaning and replacement of filter media. The filter chamber should be cleaned to remove accumulated debris, and the media should be replaced according to the manufacturer's recommendations. Additionally, the impeller and tubing should be inspected and cleaned to ensure proper functioning of the filter.

Canister Filters

Canister filters, on the other hand, are a larger and more powerful type of external filter that is commonly used for medium-sized to large fish tanks. These filters offer several benefits for aquarium enthusiasts.

  • Efficient Filtration: Canister filters are known for their exceptional filtration capabilities. They have multiple compartments that hold various types of filter media, such as mechanical, chemical, and biological media. This allows for thorough water cleaning and removal of debris, toxins, and harmful substances.
  • Versatility: Canister filters can be customized to meet the specific needs of different aquarium setups. They can accommodate a wide range of filter media and can be adjusted to control water flow rates. This versatility makes them suitable for various types of aquatic environments.
  • Easy Maintenance: Canister filters are designed for easy maintenance. They typically have quick-release valves or baskets that allow for easy access and replacement of filter media. Regular maintenance, such as cleaning, rinsing, and replacing filter media, ensures optimal performance and prolongs the life of the filter.

Filter Stability in Tank Currents

maintaining stable tank filtration

Filter stability in tank currents is a crucial factor to consider when selecting and placing a filter in an aquarium. The impact of tank currents on filter performance can greatly affect the overall health and cleanliness of the tank. Having a stable filter in the tank provides several advantages, including:

  1. Efficient Filtration: A stable filter can maintain consistent water flow, ensuring effective filtration of debris, waste, and harmful substances.
  2. Oxygen Distribution: Proper stability helps in distributing oxygen evenly throughout the tank, promoting a healthy environment for the fish and other aquatic organisms.
  3. Water Circulation: Stable filters contribute to better water circulation, preventing stagnant areas and promoting the overall well-being of the tank inhabitants.

To illustrate this further, the following table highlights the advantages of filter stability in tank currents:

Advantages of Filter Stability
Efficient Filtration
Oxygen Distribution
Water Circulation

Considering the impact of tank currents on filter performance is essential in maintaining a clean and healthy aquarium environment. By ensuring filter stability, aquarists can optimize the filtration process, promote oxygenation, and improve water circulation.

Distributing Oxygen in the Tank

To ensure the optimal distribution of oxygen in the tank, it is crucial to consider the placement and functionality of the aquarium filter. Proper filter placement can significantly contribute to the effective aeration of the tank, creating a healthier environment for the fish.

Here are some benefits of proper filter placement:

  • Enhanced oxygen distribution: When the filter is fully submerged, it helps in distributing oxygen more evenly throughout the tank. This is particularly important for fish that require well-oxygenated water to thrive.
  • Improved water circulation: Properly placed filters create currents that promote the circulation of water, preventing stagnant areas and ensuring oxygen-rich water reaches all corners of the tank.
  • Increased filtration efficiency: By placing the filter in the right spot, it can effectively remove debris, waste, and harmful substances from the water, improving overall water quality and oxygenation.

Hidden Placement of Gravel Filters

secretly concealed gravel filters

Gravel filters, unlike hang-on-back filters, can be strategically placed beneath the substrate, ensuring a hidden and discreet filtration system in the fish tank. These filters consist of a perforated plate, uplift tubes, and an air pump, with most of the components submerged underwater.

The placement of gravel filters beneath the substrate offers several advantages. Firstly, it allows for a more aesthetically pleasing tank as the filter remains hidden from view. This is particularly beneficial for aquarium enthusiasts who desire a clean and minimalist look for their tanks. Secondly, the hidden placement of gravel filters helps to distribute oxygen and water current evenly throughout the tank, promoting a healthier environment for the fish.

However, there are also some drawbacks to consider. The hidden placement of gravel filters can make them more difficult to access and maintain. Additionally, the presence of substrate above the filter may reduce its overall filtration efficiency. Therefore, it is important to carefully weigh the pros and cons before opting for a hidden gravel filter in your fish tank.

Pros and Cons of Different Filter Types

The placement of filters in a fish tank plays a crucial role in maintaining a healthy aquatic environment, and understanding the pros and cons of different filter types is essential for making informed decisions.

Here are the pros and cons of different filter types:

  • Air-powered filters:
  • Pros: Provide better stability in tank currents, distribute oxygen evenly, suitable for smaller fish in calm water.
  • Cons: Usually need to be paired with a stronger filter for proper tank cleaning.
  • Gravel filters:
  • Pros: Distribute oxygen and current evenly, hidden beneath the substrate.
  • Cons: Require more maintenance due to hidden placement, may cause noise levels.
  • Internal filters:
  • Pros: Can be placed underwater, take up less space in the room, effective at their job.
  • Cons: May produce noise levels if not properly maintained.
  • Hang-on-back filters and canister filters:
  • Pros: Filter water outside the tank, suitable for medium to large tanks.
  • Cons: Canister filters cannot be hung on the back of the tank, may produce noise levels if not properly maintained.

Frequently Asked Questions

How Do I Determine if a Filter Should Be Fully Submerged or Not?

Determining whether a filter should be fully submerged in a fish tank depends on the type of filter and its function. Factors such as stability in tank currents and oxygen distribution should be considered. Can a partially submerged filter work effectively? Is it necessary for a filter to be fully submerged in a fish tank?

Can I Use an Air-Powered Filter for a Larger Fish Tank?

Air-powered filters are not recommended for larger fish tanks due to their limited efficiency. Fully submerged filters, on the other hand, offer numerous benefits such as better stability, oxygen distribution, and improved tank currents.

Are Gravel Filters Suitable for All Types of Fish?

Gravel filters have limitations and may not be suitable for all types of fish. Alternative filtration methods, such as hang-on-back filters or canister filters, can provide more effective and efficient water filtration for different tank setups and fish species.

Can Internal Filters Be Used in Tanks With Strong Water Currents?

Internal filters can be used in tanks with strong water currents, but the submergence of the filter depends on its type and function. Proper placement and consideration of the filter's services and current generation are important factors to determine submergence.

What Are the Advantages and Disadvantages of Hang-On-Back Filters Compared to Canister Filters?

Advantages of hang-on-back filters over canister filters include their compact size and ease of installation. Disadvantages include lower filtration capacity and potential noise. Canister filters, on the other hand, offer higher filtration capacity but are bulkier and more expensive.


In conclusion, the decision of whether a fish tank filter should be fully submerged depends on the type of filter and its intended purpose.

Air-powered filters and gravel filters should be fully submerged to enhance stability, oxygen distribution, and even currents.

Internal filters offer space-saving qualities and can be placed underwater.

External filters operate outside the tank and provide varying power and capacity.

By understanding the pros and cons of different filter types, aquarists can make informed decisions to maintain optimal filtration and a thriving aquatic environment.

[ANTICIPATED OBJECTION]: Some may argue that fully submerging a filter may make it more difficult to clean and maintain. However, the benefits of enhanced stability, oxygen distribution, and even currents outweigh the potential challenges of cleaning.

Regular maintenance and proper cleaning techniques can ensure that a fully submerged filter continues to function effectively in maintaining a healthy fish tank ecosystem.